Speed-regulator for elevators



(No Model.)

W. E. NIGKERSON.

SPEED REGULATOR EDE ELEVATOES.

No. 399,068. Pat' ted Mar. 5, 1889.

l N. PETERS, Phsbtningnphar. Wuhingtm D. C.

UNM-en Sterns erreur @ritieni lVlLlIAM E. HKERSON, Ol? CAMBRIDGE,lllASSACIlVSEITS.

SPEED-REGULATOR FOR ELEVATORS.

SPECIFICATION' forming part of Letters Patent No. 399,068, dated March5, 1889.

i jjslioa'lcn fled November 30,1888. Serial No. 292,235. No `model.)

To LZZ whom it 71mg/ concern:

le it known that l, WILLIAM E. NICKERSON, i ,Y

i the sheave D', attached to the piston-rod l ot Cambridge, in thecount-5v oi Middlesex and State ol ).lzissaeliiisetts, have invented anew and useful Improvement in Safety Fluid Speeddegulators Yforlllevators, of which the lollowix1g,tal{eu in conneetion with theaccompanying d rawings, is a specilieation.

The olijeet ol my invention is to yso construct and arrange the parts oia safety-fluid speedregulator that all of the movements shall he uniformand steady, avoiding, all irregular and abrupt changes either in changeoi direction or velocity oi motion. tain by the meehanism shown in Theaeconn panying d rawings, in which-- Figure l is an elevation showingsueh parts i of an elevator as are required to illustratemy invention.ingl a part ol the cap-plate of the main cylinder of my device, theloca-lion of the pistonrod and the relief-valves being' shown; and liig.3 is a cross vertical section taken through the cap-plate on line :r o;ot Fig. and illustrates the eonstruetion and arrangement of therelief-valves.

In that class of safety speed-regulators to which my invention belongsthere has heen an irregularity oi' working caused h v thet'act thatthere is not so much fluid-space in the Cylinder when the piston is downas there is when the piston is up-that is, compensation has not heenmade ior the Huid-space oeeu.- pied hy the piston-rod when the rod is inthe c vlinder and .for the vacancy caused by its withdravml. Thisohjeetion has to some extent heen ohviated in my former inventions, andmy present device applies more particularly to that class in which long'cylinders are used.

To give additional evenness of motion and security to the device, l haveadded a `valve arrangement adapted to operate in the eapplal'e,:althoughthe said valve can he placed in the piston and work equally well.

lu the drawings, Fig. l, A represents the carriage ot' the elevator, l lthe hoistin e-rope,

and l a sheave over whieh thehoisting-rope a L valve works in a chamber,P, l'ormed in the l ll passes.

S h" Si is a safety-rope attached to the ele- This object l. atl Fig'. 2is an enlarged plan showi cylinder C is to admit oi the i'low of liquidvater-carriage, as shown, and, passingl up over the sheave D, descendsso as to pass under either by means of a pipe, as shown at H H lig, ormade in the walls ol the Cylinders.

The object of having' a (inni-passage leading,` from the auxiliarycylinder t" to the main from one side oi' the piston l to the other inits movement in the cylinder, as well as to admit of the flow ol. theexcess of lluid that I would be in the cylinder C when the piston isdown, and the piston-rod is within it.

If the pipe ll ll Il2 were omitted, then on the upward movement ol' thepiston and consequent withdrawal of the piston-rod a vacuum would beformed underneath the piston, as no oil could get down during,v theupward stroke, the pressure being` upward and against it. This vacuum isthe cause of more or less un even n ess and uncertain-ty of motion instoppin and starting the ear.

It is to he understood that the flow of liuid from one side of thepiston to the other as it moves in the cylinder C is partirilly providedfor by leakage about the piston or by oriflees made in it.

In the. cap-plate E, l have valves of peculiar construction, as shown inFigs. 2 and 3. The valve V has `an upward-projeeting stein,- V, uponwhich l place adjlisting-weights The valve has also adownward-projecting stem, Y. The two stems Y and Y" serve to keep thevalve in place and leave it Yfree to move up and down, or, in otherwords, close and open as the piston rises or lowers. rThe eapplate E, asshown Yiu lliu'. il. The ehamher lOO R has a series of openings, P P,toward the auxiliary chamber C', and a corresponding,` series, P' P',toward the main cylinder C. V2, l1`ig'. 3, is a screw-bushing insertedin the under side of the cap-plate E, to complete the chamber R and toafford a guide for the valve-stem V3, as well as a rest or stop for theshoulder V* of the valve-stem V3. The number of the valves V and theseries of openings P P and P' P' may be varied to suit the requirementsof the case. The valve V opens downwardly to admit the free passage ofthe liquid from the auxiliary cylinder C' to the cylinder C and closesonly upwardly.

By weighting the valve V, I am enabled to so balance it that it willclose at any desired upward pressure of the fluid in the cylinder C,this pressure depending upon the velocity of ascent of the piston P',which has a definite ratio to the descent of the elevator-earriage A.Thus by varying the weight IV, I can Control or fix the maximum velocityof descent of the elevator-carriage.

I Claiml. In a fluid speed-regulator for elevators, the combination ofthe safety-ropeS S' S2, the piston-rod P, and piston P', with thecylinder C, cap-plate E, valves V, auxiliary cylinder C', and pipe H HH2, leading,` from the auxiliary cylinder C' to the lower part of thecylinder C, all opera-ting together substantially as described, and forthe purpose set forth.

2. In a safety-fluid speedregulator for ele- Vators,the combination ofthe piston-rod P, piston P', main cylinder C, cap-plate E, and valve V,having adj Listing-weights V\7,with the auxiliary cylinder C' and pipeH' H H2, substantially as described, and for the purpose set forth.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, on this 28th day of Novembor, A.D. 1888.

WILLIAM NICKERso.

IV'itnesses:

FRANK G. PARKER, MATTHEW M. BLU-NT.

